Conceptual Design And Optimization Of Passenger Car Body Based On Frontal Impact

In recent years,Chinese automobile industry has experienced rapid development and become the largest automobile producer and seller in the world.In order to meet the growing market demand,automobile enterprises pay more and more attention to the development of new models,in order to shorten the development cycle,improve the design and production efficiency,so as to seize the market and ensure the long-term efficient profit.The development of new models cannot be separated from positive design.However,domestic automobile enterprises started relatively late in the field of positive design and still have huge development space.The positive development and design of automobile generally consists of three stages: conceptual design stage,detailed design stage and product improvement stage.As one of the most important assemblies of automobile,the overall structure and spatial arrangement of automobile body are completed in the conceptual design stage.Therefore,how to improve the design efficiency of automobile body in the conceptual design stage has become the key influencing the whole automobile development cycle.Supported by the innovation project of GAC research institute,the research content of this paper is devoted to the research of a frame body model modeling method that can be used in the conceptual design stage to optimize the design for forward collision problems,and can predict and evaluate the collision performance of the body in the early stage of forward design.In order to satisfy the use of the conceptual design stage,the modeling process and optimization are redeveloped to realize the automation and integration of the design process,which provides a reference for the engineering application.This paper analyzes the research results of body conceptual design at home and abroad in recent years,and discusses the importance of conceptual design stage in automobile design process.At present,the basis of the commonly used conceptual body model,such as the body,joint modeling methods,etc.are systematically studied and compared with the advantages and disadvantages,and the modeling method suitable for the research content of this paper is selected.Plastic hinge is introduced into the conceptual car body model,and the bending process of box thin-wall beam based on Kecman theory model is introduced and analyzed.Aiming at the frame model of body-in-white,a local plastic hinge model and a simplified joint model are established first,and the accuracy of these two basic models is verified through the comparative analysis of finite element simulation and detailed model.According to certain rules of simplified body modeling,the establishment of the corresponding beam passenger car shell mixed frame body,at the same time,gives the simplified plastic hinge model and joint model,at the request of the low-speed collision head-on collision simulation,and compared with the vehicle model in detail in the same condition analysis,the results show that the established framework body model in common collision performance evaluation index can better describe the vehicle model in detail,satisfy the requirement of conceptual design.For the realization of the concept model of car body modeling and optimization of integration and automation,based on Tcl/Tk language,in Process Studio and the Process manager platform to establish a complete modeling and optimization Process,including meshing,car body joints,define plastic hinge,the finite element analysis,optimization design,finally established the support collision optimization framework of lightweight car body model.Through the system test of the enterprise,the results show that the conceptual body modeling method proposed and implemented in this paper can be applied to the automation of conceptual design process,and can carry out the optimization design based on frontal collision,so that developers can evaluate and analyze the vehicle body collision performance in the early stage of vehicle body design.The optimized parameter information can provide reference for the subsequent detailed design stage.